Insulated wound core assembly for electric motors and the like



May 1, 1962 F. 2. DAUGHERTY ETAL 3,032,671

INSULATED WOUND CORE ASSEMBLY F OR ELECTRIC MOTORS AND THE LIKE Filed March 17, 1960 FIG. I I2 NVENTORS I FRANK Z. DAUGHERTY 8:

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United States. Patent 'Ofitice 3,032,671 Patented May 1, 1962 3,032,671 INSULATED VOUND CORE ASSEMBLY FOR ELECTRIC MOTORS AND THE LIKE Frank Z. Daugherty, Kent, and Albert L. Sebok, Akron,

Ohio, assignors to Ametek, Inc., a corporation of Delaware Filed Mar. 17, 1960, Ser. No. 15,582 9 Claims. (Cl. 310-214) The present invention is concerned with an insulated Wound core assembly, and more particularly with providin g a novel improved insulated wound core assembly, and specifically with providing a novel improved insulator for receiving a coil to be wound about a metal core, and a core adapted to the same.

Although the present invention is here disclosed as embodied in an assembly of a small commutating motor field core, winding, brushes and power leads, and described in corresponding terms, various features of the invention are useful in other environments.

It is the general object of the present invention to provide an improved way of providing proper insulation of a conductive coil from a metallic core about which it is wound.

Another object is to provide adequate insulation of the character described which is incorporated into an assembly at low cost.

A further object is to provide an insulator including means whereby terminal portions of conductive leads are simply yet effectively anchored.

A further object is to provide an assembly of a core, insulator, coil and other components having leads, wherein the insulator anchors and supports the leads in properly spaced relation from other components, and in such fashion that the assembly may be handled or processed as part of a larger assembly with all parts maintained in proper relation.

Other objects and advantages will be apparent from the following description and the drawings, wherein:

FIG. 1 is an end elevation of a field assembly, embodying the present invention;

FIG. 2 is a side elevation taken viewed from 22 in FIG. 1 with a portion of the field core or stack broken away;

FIG. 3 is a fragmentary view corresponding to FIG. 2, with certain portions broken away; and

FIG. 4 is a detail of lead supports and connections.

In the drawings, a stator field core of ferro-magnetic material 10 appear-ing in FIG. 1 as having a roughly inverted U-shape, symmetrical about a longitudinal vertical plane, has a yoke portion 10a embraced by a bobbin insulator structure 11 on which a field coil 12 is wound, the core having leg portions 10b suitably shaped to define two poles with opposed faces adapted to embrace an intended cooperating rotor. Although the general form of the core here shown is such as might be used in a commutating tWopole motor, it is not necessarily of such type.

The core may be fabricated with the herein noted necessary characteristics in any suitable manner, being here shown as comprised of a stack of likepunched sheet iron metal laminations held together in alignment by rivets at In any avent, the core portion received within the bobbin 11, that is the yoke portion 10a has an elongated and rectangular cross-section (see FIG. 3) and hence may be said to have a straight portion, i.e., with flatparallel top and bottom surfaces, extending through the hollow bobbin.

- The coil insulator or bobbin 11 as viewed in FIG. 3 is symmetrical about a horizontal central plane and has a rectangular spool-like form, ie, in having a body on which a coil is wound, and a generally peripheral coilretaining flange at each end. The body portion is comprised of generally flat parallelwalls 11a, 11a joined at one side by a shorter wall 11b, and on the opposite side terminating in respective similar lips 11c.

The lips have opposed surfaces mutually converging in-' wardly to end at sharp wide shoulders, so that the body portion may be considered to have a longitudinally slotted Wall opposite 11b. The width (horizontally as viewed in FIG. 3) of the lips is selected first for the insulating air gap desired in the month between coil and stack core, and also for shear strength of the lips. Thus the insulator body has the cross-sectional shape of its end-to-end opening generally conformed to that of the core portion on which it is mounted.

Flat parallel flange formations 11 11 provided at opposite ends each extend outward from each wall portion 11a, 11a, 11b and beyond the lips 110, being then perpendicular to the yoke portion of the core. The extent of the flange projections is determined by the bulk of the coil 12 to be wound; and each is carried out even further beyond 11b in a portion providing perforated tabs spaced from the outside of the coil to mount or anchor coil leads 12a, 12b, leads 16a, 16b of brushes 16 and power leads 17a, 17b.

By virtue of three apertures 21, 22, 23, opening through necked slots to the adjacent edge of the flange, and apertures 24, 25, the tab portions of the flanges serve as terminal strips to anchor and support the various leads and their connected ends. Thus considering the aperture 25 spaced inwardly from slot or aperture 23, there is defined therebetween a short nec of insulator material rigidly spaced from the outside of the coil (indicated by the rectangular dashed line in FIG. 3) about which neck a conductor 12b may be bent in a bight to anchor a terminal part of the coil winding and so also another conductor (here brush lead 16a) to be connected to the coil. The coil lead or terminal portion 12b is simply threaded out through 25 and pulled around through the slot into 23 (and if desired this being repeated for a more secure anchor); the end of the brush lead is similarly anchored, resulting in the free ends of both leads projecting inw-ard ly through flange aperture 23; the two are electrically joined as by soldering or through a metallic sleeve 19 crimped thereon; and finally as needed the lead junction is bent into a neat placement within the flange bounded space, properly spaced from the coil and other conductors.

In the specifically disclosed structure the central apertures 22 are aligned to support at spaced locations the ex ternal power leads 17a, 17b, which me thereby held in spaced relation from the coil. The end of one lead 17a is bent around and brought through on adjacent outer slot 21 (at left of FIG. 1) for connection to the other coil lead 12a previously anchored in the manner described described form including the slots and apertures 21, 22,

23, 24, 25 as an integral piece of nylon or other suitable plastic which though generally rigid is at least resilient enough to permit spreading apart of the lips 11c as the unwound insulator is slipped sideways onto the core. The lips then return inward to engage longitudinal marginal edges of the narrow core side face which is then centered relative to the longitudinal slot defined between lips 11c thereby retaining the insulator on the core. The piece as molded may have a slight convergency of the walls 11a toward the open side, thereby to effect a tighter grippingof the unwound-insulator on the core. The winding of the core of course further secures the insulator relative to the core by increasing frictional engagement.

We claim:

1. In an electrical component including a metal core and a conductive coil about the core, the combination comprising: a core portion having an elongated crosssection providing a relatively narrow lengthwise face along oneside of said portion; and a one-piece insulator of resiliently rigid material about said core portion, said insulator having-a central opening therethrough adapted to receive and generally conformed to said core portion, said insulator having a longitudinal slot along one side corresponding to said narrow face on the core, whereby the insulator may be slipped onto the core from a side opposite said narrow face, said slot being narrower than said face to provide insulator retaining lips on opposite sides ofthe slot for engaging opposite longitudinal marginal areas of said face, said side being thickened relative to the general thickness of the insulator thereby to increase the spacing of the coil from the core over the slot region; and opposed surfaces of said lips being outwardly divergent.

'2. In the combination of claim 1, said insulator including atfeach end an integral flange formation extending substantially perpendicularly out from said'core in all directions except at said slot torsupport opposite ends of the coil.

3. In the, combination of claim 2, each of said' flanges having a flange portion extending beyond said coil, said flange portions being parallel and each having a pair of apertures successively inwardly spaced from a flange edge and the edge slit inward to the outer of said apertures to provide between said apertures an anchor region for a bight in a terminal portion of the coil conductor, said flange portions having each an .additionalaperture, the additional apertures being aligned for support of a lead wire received therein in spaced relation to the coil and joinedto a conductor anchored on one of said flange portions.

4. For insulating a coil from a core therefor having an elongated cross-section providing a relatively narrow lengthwise face along one side of said portion: a resilient one-piece hollow insulator for said core portion having a central opening therethrough adapted to receive and generally conformed to said core portion, said insulator having a longitudinal slot along one side corresponding to said narrow face on the core, said slot being narrower than and centered relative to said face, integral longitudinal lips formed on respective sides of said slot for engaging margins of said face and having opposed outwardly divergent lip surfaces, whereby the insulator may he slipped onto the core from a side opposite said narrow face and thereretained by said lips, said insulator having an integral coil-retaining peripheral flange at each end extending substantially perpendicularly outward thereof and interrupted to provide access to said slot, both said flanges having parallelly-extending flange portions projecting beyond the thickness of the coil to be wound thereon; each said flange portion having a pair of apertures successively inwardly paced from a flange edge and the edge slit in- Ward to the outer of said apertures to provide between the apertures an anchor region for abight in a terminal portion of a coil conductor; the said flange portions having aligned respective additional apertures for receiving therein and supporting in spaced relation to said coil a lead a wire joined to a conductor anchored on one of said flange portions.

5. In an electrical component including a metal core of said core portion, said body being longitudinally open along one narrow side, whereby the said insulator may be slipped sideways onto said core portion; the body having a pair of respective longitudinal lips formed on opposite sides of the longitudinal opening engaging respective margins on said face of the core for retaining the body on the core; said lips having respective surfaces inwardly convergent toward said opening; and an integral peripheral flange on each end of the body extending outwardly perpendicularly to the core, each flange having a gap extending outwardly beyond said lips.

6. In the combination of claim 5, said flanges each in cluding at the side of the body a flange portion projecting beyond the thickness of the coil; each 'flange portion having a necked slot extending inward from one edge and an aperture closely spaced to and inward of the slot end to provide therebetween an anchor for a bight in a terminal portion of a coil conductor; the flange portions having aligned respective second inward necked slots adapted to receivevand support at longitudinally spaced location a lead to be connected to one of said conductor terminal portions.

7. For insulating a coil from a core therefor including a core portionhaving an elongated rectangular transverse cross-section providing a relatively narrow longitudinal face onone side: a resilient one-piece insulator having a body centrally open from end to end and generally conformed to the rectangular cross-section of said core portion, said body portion being longitudinally open along one narrow side, whereby the said'insulator may be slipped sideways onto said core portion; the body having a pair of respective longitudinal lips formed on opposite sides of the longitudinal opening engaging respective margins on said face of the core for retaining the body on the core; said lips having respective surfaces inwardly convergent toward said opening; and an integral peripheral flange on each end of the body extending outwardly perpendicularly to the core, each flange having a gap extending outwardly beyond said lips; said flanges each including at the side of the body a flange portion projecting beyond the thickness of the coil to be wound; each flange portion having a necked slot extending inward from one edge and an aperture closely spaced to and inwardof the slot end to provide therebetween an anchor for a bight in a terminal portion of a coil conductor.

8. In a fractional horsepower motor, a stator core having a core portion with substantially uniform elongated rectangular transverse cross-section; a one-piece insulator molded of elasticallvrigid material in a generally rectangular spool-like form to have a. rectangular central opening complementary in shape to the said core portion, said insulator having at one narrower side a longitudinal opening into the central opening whereby the insulator may be slipped sideways onto said portion of the stator core, said insulator including insulator locking lips formed on opposite sides of said opening for engagement with a narrower longitudinal face of the core; and a stator winding Wound on said insulator about said core; the end flanges of the insulator having portions projecting outwardly beyond the winding and plurally perforated to provide anchor regions for bights in terminal portions of the. winding. i

9. In a fractional horsepower commutating motor, as a subassembly: brusheshavingattachedflexible leads, a field core having a core' portion with substantially un form elongated rectangular transverse cross-section; a onepiece insulator molded of elastically rigid material in a generally rectangular spool-like form to have a rectangular central opening complementary in shape to the said'core portion, said insulator having at one narrower side alongitudinal opening into the central opening whereby 'the insulator may be slipped sideways onto 'said portion of the field core, said insulator including insulator lockinglips formed on opposite sides of said opening for 3,032,671 5 6 engagement with a narrower longitudinal fa e f the having permanent connections adapted for commutating core; and a fi ld Winding wound o id core; th d motor operation spaced from each other and said coil.

flanges of the insulator having portions projecting References Cited in the file of this patent wardly beyond the winding and plurally perforated to UNITED STATES PATENTS provide anchor regions for bights in terminal portions f 5 2 559 3 Schneider July 10 1951 the Winding and in the brush leads and further to pr vi e 2,592 55 Sickles et 1 Oct 19 1954 aligned respective apertures for supporting external lea s 2,858,514 H d r n (Jet, 28, 1958 leaving said assembly, said leads and terminal portions 2,902,661 Henderson Sept. 1, 1959 

